Luminaire for fluorescent lamps



Jan. 5, 1965 J. MULLER ETAL LUMINAIRE FOR FLUORESCENT LAMPS Filed July 2'7, 1962 JOSEF MULLER KARL LOWENSTEIN BY Wm W ATTORNEY United States Patent M 3,164,327 LUMEWAERE FGR FLUQRESCENT LAME S .iosef Mtiller and Karl Ltiwenstein, Neheirn-Husten, Germany, assignors to Triiux-Lenze KG, Neheim-Husten, Germany, a firm of Germany Edited July 27, 1%2, Ser. No. 212,778 Ciaiins priority, application Germany Dec. 14, 1961 3 Claims. (Cl. 240-128) This invention has reference to luminaires for fluorcscent lamps, and more particularly to composite luminaires comprising an upper supporting frame structure open at the lower side thereof, and further comprising a light-diffusing trough for closing said open lower side of said frame structure.

Luminaires of the above description call for simple, rugged and easy to handle means for securing the lightdifiusing trough to the frame structure.

It is, therefore, one object of this invention to provide improved luminaires which fully comply with these requirements.

Another object of this invention is to provide luminaires of the above description including improved snap-on fastener means for attaching the light-diifusing trough to the frame structure above it.

Still another object of the invention is to provide luminaires of the above description having snap-on fastener means which lend themselves particularly well to be associated with light-diffusin troughs made of a plastic material such as, for instance, a synthetic-resin-fiber-glass laminate.

A further object of the invention is to provide luminaires of the above description wherein the light-diffusing troughs may be made of a relatively thin material having a relatively small dimensional stability and tending to be easily deformed with snap-on fasteners means tending to preclude deformation of the light-diffusing troughs when in position and .to establish tight joints between the frame structures of the luminaries and the light-diifusing troughs thereof.

Still another object of the invention is to provide lumi naires for fluorescent lamps having improved snap-on fastener means for joining the light-diffusing trough to the frame structure, which fastener means are internal, not apparent from the outside of the luminaire and do not increase the bulk of the latter.

The foregoing and other objects of the invention and advantages thereof will more clearly appear from the ensuing particular description of the invention, as illustrated in the accompanying drawing wherein:

FIG. 1 is a vertical section of an embodiment of the invention showing the light-difiusing trough in the position it has immediately before being attached to the frame structure, or immediately following it removal form the frame structure;

FIG. 2 is a vertical section similar to that shown in FIG. 1 of the same luminaire as shown in FIG. 1 showing the light-diffsuing trough snapped-on to the frame structure; and

PEG. 3 is a section along I-I of FIG. 1 showing a detail of the luminaire of FIGS. 1 and 2.

Referring now to the drawings, and more particularly to FIGS. 1 and 2 thereof, reference numeral 1 has been applied to indicate the upper supporting frame structure of a luminaire open at the lower side thereof. The upper side of frame structure 1 is intended to be suspended from a ceiling (not shown). The fluorescent lamps and their auxiliary equipment, such as the ballast chokes, the starting switches, e-tc. (not shown in any of the figures) are intended to be afi'ixed to, and supported by, frame structure 1. Light-diffusing trough 2 closes the open lower side of frame structure 1. Trough 2 is preferably made 331M327. Patented Jan. 5, 1965 of a synthetic-resin-glass-cloth laminate, or glass fiber reinforced plastic. Both sides of frame structure 1 are provided with horizontally outwardly projecting flanges 3, FIGS. 1 and 2 showing but one of these flanges situated on one side of frame structure 1. All the parts of the luminaire of FIGS. 1 and 2 are symmetrical with regard to a vertical plane of symmetry and, therefore, it is sulficient for a full understanding of that luminaire to illustrate but the portion thereof situated to one side of the aforementioned vertical plane of symmetry. The horizontal flanges 3 are followed by outwardly downwardly flaring surfaces 4 and horizontal edge portions 5 which are bent inwardly, i.e. toward the aforementioned vertical plane of symmetry. Surface 4 is an abutment surface and is provided with a gasket 6 in strip-form extending along the entire side of the luminaire. Strip 6 is preferably made of foam rubber.

Trough 2. comprises an inwardly slanting lateral edge portion 7 at the side thereof adjacent frame structure 1 adapted to engage abutment surface 4, or gasket strip 6 respectively, by which abutment surface 4 is covered.

The structure shown in FIGS. 1 and 2 further comprises trough clamping means in the form of rollers 36 wich are serrated and adapted toreceive between contiguous serrations thereof the upper edge of the slanting lateral surface of the light-diffusing trough. This feature affords improved guiding of the light-diffusing trough into the inside of the frame structure situated above the trough.

As shown in FIGS. l3 there are substantially U- shaped bracket means within the frame structure 1 of the luminaire integral with said frame structure and including vertical flange portions 33 of which each defines a substantially horizontal slot 34. Slots 34 are open at the end thereof next to the vertical median plane of symmetry of the frame structure 1 and closed at the other or left ends thereof. The horizontal web portion of the aforementioned bracket means abuts against and is affixed to the horizontal wall portion 3 of the frame structure 1 and has a vertical extension 36 bent degrees out of the plane defined by the aforementioned web portion. Extension 36 is a spring abutment as will be more apparent from what follows and is provided with a rectangular slot or aperture 37. The luminaire of FIGS. 1-3 further comprises a substantially T-shaped supporting element 32 including a flange portion 32b having ends 31 inserted into the slots 34 in flange portions 33 and slidably guided within said slots. Supporting element 32 further includes a web portion 32a having an end inserted into, and slidably arranged within, slot 37 of spring abutment surface 36. The ends 31 of flange portion 32b each rotatably support a serrated roller means 30 which is adapted to engage the inwardly slanting surface 7 of the lateral edge portion of the light-diffusing trough 2.

A helical spring 35 is mounted on the web portion 32a of T-shaped supporting element 32 resting with one end thereof against spring abutment surface 36 and resting with the other end thereof against the flange portion 32b of supporting element 32. Thus spring 35 biases flange portion 32-1) and serrated roller means 3% from right to left, as seen in FIGS. 13. Upon insertion of the inwardly slanting lateral edge portion '7 of the light-diffusing trough 2 into the gap formed between serrated roller means 39 and a foam rubber strip 6 juxtaposed to roller means 30 the outer surface 20 of the aforementioned edge portion engages the foam rubber strip 6 and is maintained in position by the action of helical spring 35. This is shown in FIG. 2.

The web portion 32a of supporting element 32 is provided with a circular aperture 39 adapted for insertion of a rod-like tool or mandrel. When assembling or disassembling the luminaire shown in FIGS. 1-3 spring 35 is compressed, i.e. its length is shortened, whereupon a rod-like tool or mandrel is inserted into aperture 3? to maintain spring 35 in the compressed position thereof. In that position of spring 35 the ends of flange portions 31 of supporting element 32 may readily be inserted into the open ends of slots 34, or withdrawn from slots 34, through said open ends thereof.

It will be apparent from the foregoing that light-diffusing trough 2 may readily be removed from frame structure 1 and readily attached to the latter, thus minimizing the amount of labor involved in maintenance and repair work. Trough 2 may be removed from frame structure 1 by exerting a downward pull on the former, resulting in a movement against the bias of spring 35 of serrated rollers, 30 and of supporting element 32 from left to right and resulting in a release of trough 2. When trough 2 is in its upper position shown in FlG. 2 the resilient gasket strip or sealing strip 6 is elastically deformed by the action of helical spring 35, thus providing a tight seal between part 7 of trough 2 and frame structure 1..

The operation of securing trough 2 to frame structure 1 involves an upward pushing motion or thrust of trough 2 against frame structure 1, resulting in a displacement of parts 34) and 32 from left to right and in clamping of part 7 of trough 2 between gasket 6 and serrated wheel 30.

The number of points at which a light-diffusing trough 2 is clamped in position is optional and depends primarily upon the size of the luminaire and upon the weight of the trough. It is also optional Whether to provide one, or more than one, serrated clamping rollers 3d at each of a plurality of clamping points.

It will be understood that we have illustrated and described herein preferred embodiments of the invention and that various alterations may be made in the details thereof without departing from the spirit and scope of the invention as defined in the appended claims.

We claim as our invention:

1. A luminaire for fluorescent lamps comprising in combination:

(a) an upper supporting frame structure;

(b) a light-diffusing trough arranged at the lower side of said frame structure, said trough including an inwardly slanting lateral edge portion at the side thereof adjacent said frame structure;

(c) an abutment surface integral with said frame structure adapted to be engaged by a portion of said trough;

(d) a bracket integral with said frame structure defining a pair of spaced parallel substantially horizontal slots open at one end thereof and closed at the other end thereof, said bracket including a spring abutment surface arranged at right angles to the planes within which said pair of slots are situated and defining an additional slot therein;

(e) a substantially T-shaped supporting element including a pair of flange portions having ends inserted into and slidably arranged Within said pair of slots, said supporting element further including a web portion inserted into and slidably arranged in said additional slot;

( trough clamping means integral with said supporting element engaging said slanting edge portion of said trough; and

(g) a helical spring mounted on said web portion of said supporting element resting with one end thereof against said spring abutment surface and resting with the other end thereof against said pair of flange portions of said supporting element.

2. A luminaire as specified in claim 1 wherein said pair of slots are closed at the ends thereof adjacent said slanting lateral surface and are open at the ends thereof remote from said slanting lateral surface.

3. A luminaire as specified in claim 1 wherein said Web portion of said supporting element is provided with an aperture adapted for insertion into it of a rod-like tool.

References Cited in the file of this patent UNITED STATES PATENTS 2,664,343 Freedholm July 22, 1952 2,707,120 Loeb Apr. 26, 1955 2,810,824 Kaufman Oct. 22, 1957 2,916,609 Barchman et a1 Dec. 8, 1959 

1. A LUMINAIRE FOR FLUORESCENT LAMPS COMPRISING IN COMBINATION: (A) AN UPPER SUPPORTING FRAME STRUCTURE; (B) A LIGHT-DIFFUSING TROUGH ARRANGED AT THE LOWER SIDE OF SAID FRAME STRUCTURE, SAID TROUGH INCLUDING AN INWARDLY SLANTING LATERAL EDGE PORTION AT THE SIDE THEREOF ADJACENT SAID FRAME STRUCTURE; (C) AN ABUTMENT SURFACE INTEGRAL WITH SAID FRAME STRUCTURE ADAPTED TO BE ENGAGED BY A PORTION OF SAID TROUGH; (D) A BRACKET INTEGRAL WITH SAID FRAME STRUCTURE DEFINING A PAIR OF SPACED PARALLEL SUBSTANTIALLY HORIZONTAL SLOTS OPEN AT ONE END THEREOF AND CLOSED AT THE OTHER END THEREOF, SAID BRACKET INCLUDING A SPRING ABUTMENT SURFACE ARRANGED AT RIGHT ANGLES TO THE PLANES WITHIN WHICH SAID PAIR OF SLOTS ARE SITUATED AND DEFINING AN ADDITIONAL SLOT THEREIN; (E) A SUBSTANTIALLY T-SHAPED SUPPORTING ELEMENT INCLUDING A PAIR OF FLANGE PORTIONS HAVING ENDS INSERTED INTO AND SLIDABLY ARRANGED WITHIN SAID PAIR OF SLOTS, SAID SUPPORTING ELEMENT FURTHER INCLUDING A WEB PORTION INSERTED INTO AND SLIDABLY ARRANGED IN SAID ADDITIONAL SLOT; (F) TROUGH CLAMPING MEANS INTEGRAL WITH SAID SUPPORTING ELEMENT ENGAGING SAID SLANTING EDGE PORTION OF SAID TROUGH; AND (G) A HELICAL SPRING MOUNTED ON SAID WEB PORTION OF SAID SUPPORTING ELEMENT RESTING WITH ONE END THEREOF AGAINST SAID SPRING ABUTMENT SURFACE AND RESTING WITH THE OTHER END THEREOF AGAINST SAID PAIR OF FLANGE PORTIONS OF SAID SUPPORTING ELEMENT. 